Previously we assumed a default precision of 6, which made the printed
values quite odd in some cases.
This commit changes that default to print them with just enough
precision to produce the exact same float when roundtripped.
This commit adds some new tests that assert exact format outputs, which
have to be modified if we decide to change the default behaviour.
The main change is the simplification of the expression
`(10^precision * fraction) / 2^precision` to `5^precision * fraction`.
Those expressions overflow or not depends on the value of `precision`
and `fraction`. For the maximum value of `fraction`, the following table
shows for which value of `precision` overflow will occur.
Old New
u32 08 10
u64 15 20
u128 30 39
As of now `u64` type is used to calculate the result of the expression.
Meaning that before, only FixedPoints with `precision` less than 15
could be accurately rendered (for every value of fraction) in decimal.
Now, this limit gets increased to 20.
This refactor also fixes, broken decimal render for explicitly specified
precision width in format string, and broken hexadecimal render.
This reverts commit d48c68cf3f.
Unfortunately, this currently copies some warn() invocations that we do
*not* want in the debug console, such as test-js's use of OSC command 9
to report progress.
The array which contains the actual parameters is always located
immediately after the base `TypeErasedFormatParams` object of
`VariadicFormatParams`. Hence, storing a pointer to it inside a `Span`
is redundant. Changing it to a zero-length array saves 8 bytes.
Secondly, we limit the number of parameters to 256, so `m_size` and
`m_next_index` can be stored in a smaller data type than `size_t`,
saving us another 8 bytes.
This decreases the size of a single-element `VariadicFormatParams` from
48 to 32 bytes, thus reducing the code size overhead of setting up
parameters for `dbgln()`.
Note that [arrays of length zero][1] are a GNU extension, but it's used
elsewhere in the codebase already and is explicitly supported by Clang
and GCC.
[1]: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
We have outln() and out(), warnln() and warn(),
now we have dbgln() and dbg().
This is useful for printing arrays element-by-element while still
only printing one line per array.
There's no real reason to make this a debug-only formatter, on top of
that, jakt has a optional formatter that prints None/foo instead of
OptionalNone/Optional(foo), which is more concise anyway, so switch to
that.
I found this handy for debugging, and so might others.
This now also adds a formatter for TimeZone::TimeZone. This is needed
for FormatIfSupported<Optional<TimeZone::TimeZone>> to compile. As
FormatIfSupported sees a formatter for Optional exists, but not that
there's not one for TimeZone::TimeZone.
`vformat()` can now accept format specifiers of the form
{:'[numeric-type]}. This will output a number with a comma separator
every 3 digits.
For example:
`dbgln("{:'d}", 9999999);` will output 9,999,999.
Binary, octal and hexadecimal numbers can also use this feature, for
example:
`dbgln("{:'x}", 0xffffffff);` will output ff,fff,fff.
This code should not be used in the kernel - we should always propagate
proper errno codes in case we need to return those to userland so it
could decode it in a reasonable way.
This does not need to be defined in Format.h. This causes FixedPoint.h
to be included everywhere. This is particularly going to be an issue
when trying to include <CoreServices/CoreServices.h> on macOS. The macOS
SDK defines its own FixedPoint structure which will conflict with ours.
These are formatters that can only be used with debug print
functions, such as dbgln(). Currently this is limited to
Formatter<ErrorOr<T>>. With this you can still debug log ErrorOr
values (good for debugging), but trying to use them in any
String::formatted() call will fail (which prevents .to_string()
errors with the new failable strings being ignored).
You make a formatter debug only by adding a constexpr method like:
static constexpr bool is_debug_only() { return true; }
DeprecatedFlyString relies heavily on DeprecatedString's StringImpl, so
let's rename it to A) match the name of DeprecatedString, B) write a new
FlyString class that is tied to String.
Note that this still keeps the old behaviour of putting things in std by
default on serenity so the tools can be happy, but if USING_AK_GLOBALLY
is unset, AK behaves like a good citizen and doesn't try to put things
in the ::std namespace.
std::nothrow_t and its friends get to stay because I'm being told that
compilers assume things about them and I can't yeet them into a
different namespace...for now.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
This patch adds the `USING_AK_GLOBALLY` macro which is enabled by
default, but can be overridden by build flags.
This is a step towards integrating Jakt and AK types.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
C++20 provides the `requires` clause which simplifies the ability to
limit overload resolution. Prefer it over `EnableIf`
With all uses of `EnableIf` being removed, also remove the
implementation so future devs are not tempted.
Rather than casting the FixedPoint to double, format the FixedPoint
directly. This avoids using floating point instruction, which in
turn enables this to be used even in the kernel.
This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.
Creating a String object from the formatted data is unnecessary, as it
immediately gets turned into a StringView anyways.
With this change, we will no longer allocate on the heap when printing
`VirtualAddress`, `VirtualRange` and `InodeIdentifier` objects, which is
a step towards stronger OOM hardening.
This is primarily to be able to remove the GenericLexer include out of
Format.h as well. A subsequent commit will add AK::Result to
GenericLexer, which will cause naming conflicts with other structures
named Result. This can be avoided (for now) by preventing nearly every
file in the system from implicitly including GenericLexer.
Other changes in this commit are to add the GenericLexer include to
files where it is missing.
The state of the formatter for the previous element should be thrown
away for each iteration. This showed up when trying to format a
Vector<String>, since Formatter<StringView> was unhappy about some state
that gets set when it's called. Add a test for Formatter<Vector>.
For debugging purposes, it is very useful to look at a Vector in a
simple list representation. Therefore, the new Formatter for Vector
provides a string representation of the following form:
```
[ 1, 2, 3, 4, 5 ]
```
This requires the content type of Vector to be formattable with default
arguments.
The current implementation ignores width and precision, which may be
accounted for later or passed down to the content formatter.
This will just hexdump the given value.
Note that not all formatters respect this, the ones that do are:
- (Readonly)Bytes: formatter added in this commit
- StringView / char const*
- integral types
